The invention relates to protection of computer systems. More particularly, it relates to an apparatus which can be directly associated with a computer system prior to or during installation of the system, to protect the system against possible fraudulent use, damage, and/or tampering, by outside persons or influences.
Computers are currently in wide use, and consequently the information contained in them is increasingly important, as is the need to keep it confidential.
Accordingly, in most cases computer systems need reliable and effective means of protection. Examples of target systems are those operating in the scientific and security areas, and in offices involved in company management, such as accounting, payroll, inventory management, commercial trading, etc.
A great deal of study has been devoted to reliable prevention of: "leakage" of information, fraudulent use of information, and sabotage.
The research on data protection has been directed along two principal lines:
more or less complete physical protection of the computer system; and PA1 "intellectual" protection of the contents of the computer system. PA1 a plate on which the CPU and the computer monitor are disposed, and PA1 articulated walls which enable one to enclose the CPU, monitor, and keyboard in a container by folding-over the walls and sliding them toward the bottom of the container. When the operator wishes to begin work, he must "set up" his equipment, i.e. he must open the container, raise the CPU and monitor to the desired height, position the keyboard, and possibly position various retractable document support surfaces, etc. Then when finished working he must perform these operations in reverse; indeed, for effective protection the operations must be performed each time the operator leaves his post. It is seen that from the practical standpoint, the obstacles to success are formidable, because the sequence of operations is tedious and time-consuming, in addition to the fact that it interrupts work in progress. PA1 Ger. Gbm. 89 11 024.2 teaches the concept of enclosing the CPU in a housing having openings for ventilation and for passage of connections. A trapdoor or sliding door providing access independent from that of the principal opening of the housing is provided to provide access to a key for starting the CPU, or access to a switch. The computer is allowed to function fully or not at all. There is no option of allowing the computer to operate without providing access to data. PA1 a display element, PA1 means for gaining access to data, and optionally PA1 a device for printing data. PA1 The means for gaining access to data comprise a keyboard; PA1 The enclosure means are designed to also enclose one or more elements associated with the computer system; PA1 The enclosure means are supplied with external connectors which enable connection to at least one peripheral device; PA1 The security circuit is connected to the means for gaining access to the data; PA1 The computer system further comprises a printer element for printing data, disposed outside the enclosure, and the security circuit is connected to this printer element; PA1 The security circuit is connected to the display element; PA1 The security circuit is independent of the computer system; PA1 The security circuit comprises a switch disposed in the link connecting the means for gaining data access to the CPU and; PA1 The door or the like is furnished with mechanical means for locking and unlocking, and electronic control means are associated with these mechanical means.
By "physical protection" is meant the use of an apparatus or other means which enable physical isolation of the parts of the system containing the information sought to be protected, or blocking of the physical means of access to such information. This type of apparatus or other means is intended to prevent theft or unauthorized use of information, and also any risk of damage by environmental influences such as heat, dust, fire, and/or water.
Cabinets, disk files, and other containers for diskettes, provided with a key lock or other entry control device, do not provide reliable mechanical resistance to unauthorized entry or use. Moreover, often they are stored in office rooms along with other documents without particular selectivity and without protection over and above that afforded to ordinary items. As a result, they can be easily removed by a thief, along with their contents, particularly since they generally are of small dimensions. Of course, the theft of the data storage media and containers themselves is generally not of high economic impact. Instead, the more serious impact results from the loss of information.
Operators regard these "protective" measures as onerous, and in practice the measures tend to be implemented only in the case of a prolonged absence of the operator.
It is also known to employ removable hard disks to store basic data. Their drawbacks are that they are costly and of generally low speed, and further that they only offer protection if stored in a reinforced cabinet at the end of each work session. The technique requires cumbersome manipulations, and necessitates interruption of work in progress. Consequently it tends to be employed only in the case of a prolonged absence, similarly to the abovementioned measures.
Other means of protection have been considered for specific applications, such as key means to lock the keyboard, anti-theft markings, brackets to fix equipment to the support on which it is held, etc. These types of protection are effective only under limited circumstances.
In this connection one might mention boxes and cabinets which are shielded and/or are provided with fire resistance means. These are generally used for storing disks, diskettes, cassettes, and magnetic tapes.
It would be impractical to also store the essential equipment (e.g. central processing unit (CPU), monitor, keyboard, etc.) in such enclosures.
Existing CPUs generally comprise a housing fixed to a chassis by screws, and have one or more front ports for diskette readers or cassette players. The connection between the keyboard and the CPU is established by a relatively simple key lock. Unfortunately, even if the key is used conscientiously to isolate the keyboard, the housing can be opened via the screws, and access thereby can be obtained to the interior components, particularly the switches. In this way, switches can be shorted to avoid the protective means; and no special equipment is needed for this. Furthermore, the described protection means are merely physical and only relate to the contents of the housing. Among other things, no specific protection is afforded to the printers.
With the aim of providing physical protection which is more comprehensive and effective, it has been proposed to enclose the computer and its associated elements in a special mobile container having a key lock. In this regard, Eur. OS 0,172,762 describes an assembly which is comprised of
Other furniture items and integrated computer stations have been proposed, but these too are time-consuming to implement. In general they have the same drawback that they leave the front panel free whereby the diskette- or cassette drive(s) can be accessed. This drawback of the formerly proposed systems is problematic in that, in the case of software-based protection systems, a person can evade the protection by interrupting and then reestablishing the power supply, causing the operating system to re-boot. The person can then intervene by inputting information.
To summarize: All of the known apparatuses intended to provide physical protection to a computer system are found to be time-consuming and impractical to use, and likewise fail to meet the esthetic criteria often desirable in a work environment. Moreover, their most important drawback is their limited effectiveness which owes to the fact that they still leave the operating system and/or the monitor and/or the printer accessible to unauthorized persons such as persons passing through the office.
Faced with these deficiencies, the approach of more recent studies has been to try to develop more advanced software-based protection. This type of protection is in the "intellectual protection" category mentioned above, in particular, neutralization of electronic access to the information.
"Intellectual protections" may be divided into three categories: apparatus employing a password, apparatus employing data encryption, and "anti-virus" programs.
In the first category, a password is employed to control access to an operating system or a given application, locally or on a network. This method of protection requires rigorous control. Experience shows that a password deemed secret tends to become known to numerous unauthorized persons, either because the password is simple (a date of birth, first name, etc.) or due to an annotation of the password which is accessible or is thinly disguised and thus easy to figure out, or even by reason of closeness to another password. In order to be properly effective, an apparatus employing passwords must require use of the password whenever the operator leaves his post. Thus for protection to be effective, the operator must terminate any operation in progress whenever he leaves his post. This is extremely constraining, and causes substantial loss of time, such that eventually the operator tends to only use the password when he will be absent for a prolonged period. Nonetheless, password protection is of value when combined with other means.
Data encryption means render data unintelligible by the ordinary means of the operating system. Their purpose is to protect the data proper but not the programs which process the data. Their preferred domain is thus the processing of data. Data encryption may also be employed to introduce a certain "resistance" to accidental loss of data. Nonetheless, the technique retards data transfer. Moreover, in order to be utilized, the equipment must be provided with an encryption algorithm and the codes therefor; this renders the method vulnerable and lowers the degree of security provided. Encryption has spawned a corps of decryption specialists who neutralize the encryption by employing mathematical decryption techniques. Accordingly, only relatively vulnerable encryption systems are currently in the public domain, while more sophisticated systems are reserved for very few specific applications such as defense classified information.
Recently, a new menace has appeared, the computer "virus". This is a program which "infects" existing programs in a given computer system. The "infection" can then be transmitted to other files. The deleterious effects of viruses can cause unexpected reactions in the system or the appearance of spurious messages. More seriously, viruses can partially or entirely destroy or modify data and programs. Viruses also can be devised to release confidential information to a spy. In order to guard against this new type of invasion and sabotage, "anti-virus" programs have been developed to protect computer systems by detecting the presence of viruses in executable files, under a regime of monitoring and control which can be varied to operate continually or upon command or upon each transfer of data to or from the outside, or systematically in the final phase of a system shutoff. However, these "anti-virus" programs only protect in specific cases--when the means for detecting of a virus have become known, the authors of the virus find new ways to evade such means.
Based on the preceding, it may be stated that protection software, which provides only "intellectual" and not physical protection, is vulnerable to evasion by specialists, be they professional or amateur. Nonetheless, protection software is a useful technique to be used in combination with other means, particularly when the system is connected to a network. However, the fact that such software is slow and is difficult and costly to adapt often serves to limit its application. In general, successful use of such software requires at least one computer programmer to deal with incompatibilities which can arise with the application software in use.
Eur. OS 0,235,615 discloses a security apparatus having a locking key on the housing of the CPU, which key operates a switch which blocks the diskette drive, thereby completely blocking operation of the computer.
The present invention remedies the above-described drawbacks by proposing an effective protective apparatus for computer systems, which apparatus is simple and easy to install and use, and which in particular enables protection from unauthorized access to data, but without interrupting operation of the CPU. It additionally enables protection of the hardware and other equipment against theft and against aggression by environmental influences such as heat, dust, fire, water, etc.
Toward this end, a principal feature of the present invention is a protective enclosure for a computer system, for protecting the computer system by confinement, which computer system comprises at least one central processing unit (CPU) and input/output peripherals comprising:
The enclosure comprises enclosure means equipped with a door or the like, which enclosure means are intended to house and confine at least one CPU of the computer system. The enclosure further comprises means for locking and unlocking transmission of a signal, which locking/unlocking means are associated with the enclosure means, to neutralize electronic access to the data contained in the computer system.
The means for gaining access to the data are disposed outside of the enclosure. The door or the like has closing means which, upon actuation, actuates the locking means, which locking means have at least one contact controlled by the door or the like of the enclosure. The contact is intended to control a security circuit which comprises a switch disposed in at least one of the links which connect the input/output peripherals to the CPU. The switch is connected so as to neutralize only the means for gaining access and not operation of the CPU.
According to other preferred embodiments of the present invention:
The invention will be better understood with the aid of the following detailed description of an exemplary embodiment, with reference to the accompanying drawings. The exemplary embodiment is offered for the purpose of illustration and does not limit the scope of the invention.